[alpacassei]

Cork is pretty easy to cut through but i have had a few pieces break at thinner points - still useable just not a full tunnel.

Kaytee Clean and Cosy is safe, I’ve never seen the cancer warning on the UK stuff and in the US its the generic “found to cause cancer in the state of California” warning that is on almost anything. Definitely recommend it, my hamsters love C&C for nesting and burrowing!

For the platforms, personally I would do one full level platform at the around 40cm height or several overlapping platforms with 20 between them. That way theres no fall risks.